, also Ito Shizu Sen (糸静線) is a major fault on

Honshu , historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island s ...

island that runs from the city of

Itoigawa is a city located in Niigata Prefecture, Japan. , the city had an estimated population of 41,333, and a population density of 55 persons per km2. The total area of the city is . Geography Itoigawa is located in the far southwestern corner of ...

Niigata Prefecture is a prefecture in the Chūbu region of Honshu of Japan. Niigata Prefecture has a population of 2,227,496 (1 July 2019) and is the fifth-largest prefecture of Japan by geographic area at . Niigata Prefecture borders Toyama Prefecture and ...

, through Lake Suwa to the city of Shizuoka in

Shizuoka Prefecture is a prefecture of Japan located in the Chūbu region of Honshu. Shizuoka Prefecture has a population of 3,637,998 and has a geographic area of . Shizuoka Prefecture borders Kanagawa Prefecture to the east, Yamanashi Prefecture to the northea ...

. It is often confused with the

Fossa Magna Fossa Magna is a great rift lowland in Japan. It is often confused with Itoigawa-Shizuoka Tectonic Line. However, Itoigawa-Shizuoka Tectonic Line is a line; Fossa Magna is an area. Fossa Magna is Latin for "great crevasse". This name was given by ...

(Great Fissure Zone), a geological feature it forms the western boundary of.

Seismic activity

Recent significant earthquakes on this tectonic line include: * M5.4; 30 June 2011; epicentre near

Matsumoto, Nagano is a city located in Nagano Prefecture, Japan. Matsumoto is designated as a core city since 1 April 2021. , the city had a population of 239,466 in 105,207 households and a population density of 240 persons per km2. The total area of the city ...

; 1 death, 17 injuries. * M6.7; 22 November 2014; epicentre near

Hakuba, Nagano is a village located in Nagano Prefecture, Japan. , the village had an estimated population of 9,007 in 4267 households, and a population density of 48 persons per km2. The total area of the village is . Hakuba is an internationally renowned s ...

; 46 injuries. Japanese-language Wikipedia entry

References

Geology of Japan Seismic faults of Japan Geography of Niigata Prefecture Geography of Shizuoka Prefecture Geography of Nagano Prefecture {{tectonics-stub